Problem: Solve for $k$ : $27 = 19 + k$
Explanation: Subtract $19$ from both sides: $ \begin{eqnarray} \\ \hphantom{27 {- 19}} &\hphantom{=}& \hphantom{k} \\ 27 &=& 19 + k \\ \\ {-19} && {-19} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 27 {- 19} &=& k \\ \end{eqnarray} $ Simplify. $ k = 8$